Validations That Occur Before a Takeover

When a takeover is initiated by using the geopg takeover command,
the data replication subsystem runs several validations on both clusters.
These steps are conducted on the original primary cluster only if the primary
cluster can be reached. If validation on the original primary cluster fails,
the takeover still occurs.

First, the replication subsystem checks that the Hitachi TrueCopy or Universal Replicator device
group is in a valid aggregate device group state. Then, the replication subsystem
checks that the local device group states on the target primary cluster, cluster-newyork, are not 32 or 52. These values correspond to a SVOL_COPY state, for which the horctakeover command
fails. The Hitachi TrueCopy or Universal Replicator commands that are used for the takeover are described
in the following table.

The-t option is given when the fence_level of
the Hitachi TrueCopy or Universal Replicator device group is async. The value is
calculated as 80% of the Timeout property of the protection
group. For example, if the protection group has a Timeout of
200 seconds, the value of -t used in this command will be
80% of 200 seconds, or 160 seconds.